Pump Specifications for Fire Fighting Systems

General Requirements

The pump shall furnish not less than 150% of rated capacity at a total head not less than 65% of the total rated head.
The pump shut-off head should be at least 5% more than rated head but less than 20% of rated head for all pump types except Multi Stage (Single or Multi Outlet) and Vertical Turbine design. For these 2 types shut-off head should be less than 40% of rated head.
For Main Fire pump, the prime mover can be

Electric Motor (TEFC Design)
Diesel Engine (Radiator Cooled or Heat exchanger Cooled)
SPDP Design motors are not recommended for fire duty as they are not advisable to work in conditions with dust and low ventilation. Also, the efficiency of SPDP design motors is less than TEFC design motors as efficiency is a function of motor temperature. (Source: Bureau of Energy Efficiency)

Open Well / Deep Well submersible pumps are not recommended for fire duty.
Flexible Coupling is to be used to couple pump and motor of Main Motor Driven Fire Pump and Jockey Pump. In case when Horizontal End Suction Back Pull-out design pump is used, a spacer type flexible coupling is preferred.
Depending on the nature of Hazard and factory / building layout, the flow rate (capacity) is informed by fire authority in provisional NOC. The designated fire contractor should submit hydraulic calculations for each project in which the head calculation is indicated. It is the pump manufacturer who then decides the suitable prime mover KW/HP.
The colour code used for main fire pump and Jockey Pump shall be RUBY RED (RAL code 3001) with minimum 80 microns DFT.
Drain opening shall be provided on pump casing so that all the water from the pump casing can be drained.
The pump can be grease lubricated or oil lubricated.
The shaft shall be provided with a sealing arrangement consisting of a stuffing box having adequate depth to accommodate required number of packings and water seal cage, if required. Alternatively, mechanical seals can also be used for sealing arrangement. Normally for main fire pumps (motor / engine driven) mechanical seal is not recommended.
Coupling guard should be provided to cover rotating flexible coupling.
Pump performance characteristic should be of continuously rising type.
A directional arrow shall appear on each pump indicating the direction of rotation of the pump.

Motor for Motor Driven Pump shall be selected such that it does not overload at the condition of 150% of rated discharge.
Engine, after correction for altitude and ambient temperature shall have bear engine horse power rating equivalent to the higher of the following values:

20% in excess of the maximum Brake Horse Power required to drive the pump at duty point or
Brake Horse Power required to drive the pump at 150% of rated discharge

The Material of Construction for key components of main fire pump (Motor Driven & Engine Driven)

and jockey pump shall be as follows:

Pump to be tested at Pump Manufacturer’s factory test bed for Head Vs Capacity.
The relevant pump testing standard to be followed as defined by pump manufacturer. E.g., IS 9137
Performance curve shall be plotted showing total head, efficiency, Brake Horse Power for minimum 5 duty conditions. Shut-off head point, Duty point, 150% capacity point should be amongst 5 Duty conditions.
Always use factory assembled fire pump set (Motor Driven / Engine Driven)